Car Crashes: Why do some car crashes produce only minor injuries?

How can a single crash of a car into a wall involve three separate collisions? Griff Jones, award-winning science teacher, returns to the Insurance Institute for Highway Safety's Vehicle Research Center to answer these questions and to examine the laws of nature that determine what happens to the human body in a crash.

Jones reviews levels of organization in the body and explains how body cavities house and protect major internal organs. Through creative experiments, he explores how the third collision can cause injuries to organs. He introduces the concepts of stress and strain. He demonstrates how shockwaves can damage tissue and what happens at the cellular level.

Tools from the field of injury biomechanics, like biofidelic crash test dummies, help doctors and engineers determine what works to reduce injuries and deaths in crashes. The key to preventing injuries in any type of crash, whether it's in a race car or a family sedan, is to reduce forces on occupants.

Extending impact time, keeping the occupant compartment intact, and tying occupants to the compartment are what keep people safe in car crashes when physics meets biology.